1.1 This specification covers the functional dimensions and tolerances for tapered cones of proximal femoral stems and the bores of mating ceramic and metal heads.

1.2 This specification does not cover the dimensions of proximal femoral stems other than the cone portion, nor does it cover the dimensions of the ceramic/metal femoral heads, other than the inside tapers.

1.3 The dimensions stated in SI units are to be regarded as the standard.

1.4 The purpose of this specification is to codify matching bore and cone combinations for easy identification. Nonetheless, components from different manufacturers should not be mixed because the combinations of tolerances within the family, surface finish, and configuration from the different manufacturers may not have been validated through axial load strengths or fatigue strength.

1.5 The codification described in this specification represents the most current state of the art at the time of balloting. Future additions can be made but because of the time required to revise the specification, it is recommended that the manufacturer of new combinations label their components with at least the angles until such time that new code letters can be established in accordance with future revisions of this specification.